be2net: cleanup wake-on-lan code

This patch cleans-up wake-on-lan code in the following ways:
1) Removes some driver hacks in be_cmd_get_acpi_wol_cap() that were based
on incorrect assumptions.
2) Uses the adapter->wol_en and wol_cap variables for checking if WoL
is supported and enabled on an interface instead of referring to the
exclusion list via the macro be_is_wol_supported()

Signed-off-by: Suresh Reddy <suresh.reddy@emulex.com>
Signed-off-by: Sathya Perla <sathya.perla@emulex.com>
Signed-off-by: David S. Miller <davem@davemloft.net>